An expert system has been developed by OncoMetrics that provides a disease free survival prognosis for individual breast cancer patients. It has been used as an informational service that has been commercially available for three years from Dianon Systems, Inc. of Stratford, CT. Three hundred individual patient reports care requested each month by treating physicians in the US and in Europe. Physicians use the expert system to help in making treatment decisions and to counsel patients. Survival data were used in part of the development of the expert system. However, survival data do not have clean end points compared to disease free survival data. The initial goal is to develop an improved expert system using only disease free survival data that are available. The longer range goal is to develop an expert system to improve therapy. International Breast Cancer Study Group clinical trial VI is underway involving 1400 patients. The protocol was designed in large part as a test of OncoMetrics' computer model studies. Our analysis of five year data suggest that treatments based on the expert system are more effective than conventional treatments. However, trial statisticians wants to wait for further follow-up. PROPOSED COMMERCIAL APPLICATION: OncoMetrics, Inc. develops information products that are marketed to oncologists by Dianon Systems, Inc. A current prognostic product for breast cancer provides market differentiation for a Dianon $5 million product line. The OncoMetrics product is provided upon request and at no additional charge to Dianon customers.